diff --git a/main.c b/main.c
index 13539a4..e1cdf2f 100644
--- a/main.c
+++ b/main.c
@@ -278,16 +278,22 @@ int main(int argc, char* argv[])
 	}
 	
 	struct eismultiplexer multiplexer;
-	if(eismultiplexer_connect(&multiplexer, config.serialSet ? config.serial : 0))
+	int ret = eismultiplexer_connect(&multiplexer, config.serialSet ? config.serial : 0);
+	if(ret)
 	{
 		char serialStr[5];
 		snprintf(serialStr, sizeof(serialStr), "%04hu", config.serial);
 		printf("Can not connect to EISmultiplexer device%s%s\n",
 			   config.serialSet ? " with serial " : "", config.serialSet ? serialStr : "");
+		if(config.verbose)
+			printf("eismultiplexer_connect ret %i\n", ret);
 		return 1;
 	}
 
-	int ret = 0;
+	if(config.verbose)
+		printf("eismultiplexer_connect ret %i\n", ret);
+
+	ret = 0;
 
 	if(config.interactive || config.pipe)
 	{
diff --git a/options.h b/options.h
index 4295a0a..9c1d166 100644
--- a/options.h
+++ b/options.h
@@ -44,6 +44,7 @@ static struct argp_option options[] =
   {"pipe",			'p', 0,				0,	"run in pipe mode" },
   {"serial",		's', "[NUMBER]",	0,	"serial number of device to connect to"},
   {"list",			'l', 0,				0,	"list commands"},
+  {"verbose",		'v', 0,				0,	"enable verbose debug prints"},
   {0}
 };
 
@@ -61,6 +62,7 @@ struct config
 	char* commands[MAX_COMMANDS];
 	size_t command_count;
 	bool list_commands;
+	bool verbose;
 };
 
 static error_t parse_opt (int key, char *arg, struct argp_state *state)
@@ -89,6 +91,9 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state)
 	case 'l':
 		config->list_commands = true;
 		break;
+	case 'v':
+		config->verbose = true;
+		break;
 	case ARGP_KEY_ARG:
 	{
 		if(config->command_count+1 > MAX_COMMANDS)